\section{What is a module developer?}\label{what-is-a-module-developer}

A module developer is someone who is going to add to the simulation capabilities of EnergyPlus. Someone, for instance, who is interested in adding code to model a new type of HVAC equipment. The most straightforward way of doing this is to create a new program module -- hence the term ``module developer''.~~ Another kind of module developer would be the adaptation of an existing ``legacy'' code to EnergyPlus.

In EnergyPlus, one of the first steps in creating a new component model is to define the input. So, before we discuss modules in more detail, we must first describe the EnergyPlus input.
